1. Field of the Invention
The present invention relates to a digital signal multiplexer comprising a multiplexing portion in which first plesiochronic 139.264 Mbit/s signals or 564.992 Mbit/s signals in first channel portions are converted by stuffing and superimposing of auxiliary signals into first synchronous intermediate time division multiplex signals and in which a multiplexer interleaves these bit-by-bit into a first time division multiplex signal of a higher order, and comprising a demultiplexer portion in which a second time division multiplex signal of higher order is separated by a demultiplexer into second intermediate time division multiplex signals and in which these are converted in second channel portions into plesiochronic 139.264 Mbit/s signals or 564.992 Mbit/s signals upon destuffing and desuperimposing.
2. Description of the Prior Art
A multiplex and demultiplex arrangement of a type generally set forth above is disclosed in the German allowed and published applications 28 14 000 and 28 14 001.
A European hierarchy has been created for digital transmission systems, the hierarchy being described in the periodical "Telcom Report", Vol. 2, 1979, Special Issue, Digital Transmission, pp. 16-20. The fourth level of this hierarchy works with a bit rate of 139.264 Mbit/s. The American hierarchy contains bit rates of 1.544 Mbit/s, 3.152 Mbit/s, 6.312 Mbit/s, 44.736 Mbit/s and 274.176 Mbit/s.
The CCITT Yellow Book, Vol. III-Fascicle III.3, Digital Networks-Transmission Systems and Multiplexing Equipment, Geneva, Nov. 10-21, 1980, pp. 218-220, recommends a line multiplexer which converts four 139.264 Mbit/s signals into one 564.992 Mbit/s signal and vice-versa.